T-15 vs. T-14 in a 225V6

I have access to a Dauntless OEM T-14 bell-housing that is 9" deep and uses no adapter (direct bolt-up) so can I bolt a T-15 directly to this housing? The T-15 input shaft (stick-out) is 8-5/8". Any body know if this will work or what I need to do to make it work. TIA.

 

The v6 t14 stick out is 9.5" according to my chart. And the bearing retainer on the t15 is larger in diameter. Pilot on the T15 is larger than the t14. Its doable with a true Buick Bellhousing instead of the 1971 model you have.

 

If I recall correctly the 1971 bellhousing is 8-15/16" deep.
The optimum maindrive gear needs to be 3/8" longer than the bellhousing is deep.
Therefore the shorter 8-1/2" stickout length maindrive gear from a T15 will not work.
However you could custom shorten a maindrive gear from a T15 with the longer maindrive.
The AA T15 to BOP adapters are a 1-5/8" thick adapter that is to be used with the early Dauntless bellhousing (6-5/16 " deep).

I'm planning to make a 5/8 thick steel adapter plate to mount onto an early type Dauntless bellhousing.
I will need to shorten the maindrive gear accordingly.
This will allow me to leave the engine and transmission support crossmember in their exact original locations.
Therefore no modifications to the steering or to the propeller shafts are needed.

 

Mcruff are you saying the bearing retainer hole is smaller on the T-14 which would mean the bell-housing would have to be milled to fit the T-15? If I used Novak pilot brng PB-6914T which is the 3/4" shaft size of input gear and it fits the outside large hole in the end of the crank instead of the inner smaller one that should move the pilot brng out the 7/8" needed to make the diff for the T-15's shorter shaft vs T-14's. Am I right on this?

Oldtime I may have to go that route. Just don't know yet. I am trying to stay away from those expensive adapters if I can. Any thoughts on comment above about using the bigger Pilot bearing which fits the outer hole on end of crankshaft? I think it's 2+ inch dia .

 

Might contact Sparky. He just did this and can probably clue you in.
The length of the Jeep CJ T-15 input shaft is the same as the Jeep CJ V-6 T-14 is the same. The pilot is a different diameter as is the front bearing retainer. I can't remember for sure if the spline count is the same and same diameter but want to say there is a difference in diameter. Again, can't remember for sure.

 

According to AA the stick out of the T15 in jeeps is 8.5" and the v6 t14 is 9.5", the inline 6 t14 is listed as 8.5" though.

Same spline count 1 1/8" -10.

 

DOH! That must've been what I was thinking....

 

I tried looking back through Sparky's postings but was not able to find much direct info on the install itself. The problem I have is I don't have a T-14 to measure the bearing retainer and the ~9" T-14 bell-housing is several miles away. So are the bolt holes on the trannies the same pattern/distance? Now with the 1" diff stick-out, this still brings me back to the pilot brng. If I use the larger outer crank hole instead of the smaller inner one, that should make up for the 1" diff in length between the two trannies shaft lengths, correct?

 

The bolt pattern on the T14 and t15 are the same, the t15 has a larger diameter bearing retainer and pilot tip, the length cannot be made up, you really need to get the true Buick bellhousing where you can make a plate spacer. The 71 Bellhousing you are talking about was designed with the t14 in mind only, it was not used with any other transmission that I know of. This bellhousing is whats stock in my jeep and was available in 1971 only.

 

Here we go. I hope you guys can read this!!

 

Thanks for the chart. I will try to blow it up and maybe I can read it clearer. I have the standard Bell for 225V6 to T-86 with the cast iron adapter but the retainer hole in the adapter is too small for the T-15. The T-15 will bolt to the T-86 adapter if I have the retainer hole enlarged. This will give me more to work on so it has been very helpful. Thanks a bunch.

 

Yes like McRuff says the T-14 and T-15 have the same bolt/mounting pattern.
I really couldn't read the chart either.
Here are some various dimensions that should help.

Early Dauntless bellhousing = 6.25 depth.
Early Dauntless BOP adapter = 2.875 depth.
1971 Dauntless bellhousing = 8.9375" depth.

T14 stickout measures 9.375" not 9.5".
Both T86 and T14 bearing index = 4.25"
T15 index is about 4.868"

T15 stickout =
8-1/2"..... @ 10-7/8" OAL
11" .........@ 13-3/8" OAL
11-1/2"... @ 13-7/8" OAL
12-7/8.... @ 15-1/4" OAL

Previously I mentioned the standard engine mount location and the standard rear engine support location (AKA transmission support).

The D-225 engine location never changed from 1965 through 1971.
The rear engine (transmission) support crossmember and the insulator did change.
The Dauntless CJ evolved away from the time proven "standard".
When I say transfer case standard I mean 1945 through 1971 4 cylinder (original) locations.
This long time standard positions the TC mounting face 2.625 rear of the crossmember centerline.
The change from T86 to T14 required the use of different rear insulator locations because those transmissions are of differing lengths.
That's why the transfer case snubber design/location was modified from that of the 4 cylinder jeeps.
T14 located the transfer case back further and required a change of the propeller shafts.
T14 moved the transfercase location away from this long time standard.

I also came up with what I consider the standard length between the D225 engine/bellhousing face and the transfercase mounting face.
This combined standard length is 16.9375 " between the D-225 and D18.
Using my standard I am able to theoretically install various depths of bellhousings, various bellhousing adapters, various transmission lengths and various transfer case adapters.
This enables me to visualize how various drive combinations will fit.

If the engine is not repositioned it negates the concerns of radiator, firewall and Ross steering clearances.
Propeller shaft lenghts are only a concern if the transfercase is positioned away from the 4 cylinder standard.

 

At the risk of :dead horse:

As I understand this, Ken has given you the info you need (basically the same as what's in Mike's table, but more legible).

You have data for the T-15 bell with AMC engines, which bolts up to either the intermediate T-14 or T-15. The T-15 stickout for CJs will be 8.5", with the rest of the lengths used for the various V8 FSJ applications.

The GM-style BOP bell has a 6.3125" depth, so that leaves roughly 2" of length for your BOP to T-15 adapter. To get the same pilot location as the T-14 V6 had, your new plate adapter should be (V6/T-14 plate adapter length minus the difference in the stickouts): 2.875 - (9.375 - 8.5) = 2" exactly.

The T-15 is going to be a little longer than the original T-14 (can't read the chart well enough to give an exact figure), but I expect the thinner plate adapter will mostly make up for this.

 

I coreccted the table so its my readable. All that info came directly from Advance adapters. The chart covers everything including autos and other manual boxes. What I posted is only 1/3rd of the chart.

 

I frequently run into problems when using AA specifications.
Usually they are correct but far too often their given numbers are as much as 3/8" off.
The 9-3/8" stickout length that I claim for T86 is taken from my own measuring.

Not correct because you did not allow for pilot depth. Let me explain.....
I believe that the optimum maindrive stickout length for D-225 is 3/8" longer than the bellhousing used, plus the adapter if any.
I figure this by running a straight edge across the rear of a D-225 and observing its relation to the crankshaft pilot.
The pilot tip itself is 3/4" long.
Extends 3/8" longer and is also 3/8" shy of the engine mounting plane.

That's why AA T15 / BOP adapter is 1-5/8" thick for use with 8.5" stick out.

 

Mcruff thanks for the clear readable chart. I had a couple of the measurements wrong. Much better now.

timgr don't worry about beating a dead horse. It all helps very much to confirm my understanding and I imagine it has helped others as well.

oldtime this cleared up a lot of frustration for me because I don't have a bunch of parts that I can line up and measure. So let me digest all this info and see where I set with this. All you guys, I certainly appreciate your time and info on this. I am sure I will have a few more questions so please don't go too far. Walt.

 

Yes, stickout is not the same as bell depth. My mistake.

I'd use the same method, but use the T-15 measured bell depth instead of the stickout.

New plate thickness = old plate thickness - (new bell depth - old bell depth).

This would give you the same pilot tip location wrt the front of the bell as the original setup. This is what you were suggesting Ken, no?

 

Sparky I may have to ask you more questions later but the pilot that Herm made for you, was it for the small hole in the end of the crank or the big one. I know the center of the pilot is 3/4".